Whether canister or upright, vacuum cleaners in all of their designs and permutations have become increasingly popular over the years. In general, vacuum cleaners incorporate a suction fan motor, attendant dirt cup or dust bag and a nozzle assembly fluidly and mechanically connected to one another that suck up dirt and dust during operator movement across a dirt-laden floor. Specifically, an agitator within the nozzle assembly rotates to beat the nap of a carpet and dislodge dirt and dust during a time when an operator manipulates the cleaner back and forth. Dirt and dust then enter the cleaner and flow in an airstream toward the motor. Somewhere upstream of the motor, the dust and air are separated and particles are trapped in the dirt cup or dust bag.
While dirt cups allow users to visually inspect whether the cup is full and requires dumping, users of cleaners with dust bags have little, if any, indication external to the cleaner of when the dust bag becomes full and needs replacement. While some cleaners have incorporated bag full indicators, many require sophisticated algorithms, including fuzzy logic, complex mechanical arrangements, including pistons, springs or other, and/or audible alarms. In this regard, sophistication and complexity adds costs while audible alarms can annoy users.
Accordingly, the floor care arts have need of simple, yet effective, bag fill indicators and arrangements therefor.